The invention relates to a tool to be implemented as a grinding ring or grinding disk for the mechanical surface treatment by friction of an object. For example, the tool may be used for brushing, polishing, shining, cleaning, wetting or drying. The tool includes a cut and processed fleece of fibers.
The mechanical surface treatment is used for working numerous products including metal, wood, stone, glass, leather, synthetic material and the like, such as for example kitchen utensils, flatware, instruments, armatures, notches, grooves, frames of doors, windows, profile rods, industrial parts, jewelry and musical instruments as well as for the maintenance and care of floors, walls, glass panes, tiles and the like.
In polishing, the surface treatment is implemented in several steps with the graduated use of different tools or tool configurations which generate an increasingly finer surface. These tools include polishing rings or disks which are composed of several layers of woven textiles and in general are disposed on a common axis of rotation on a clamping ring. For polishing rings, the textile is cut into strips, folded, and fastened annularly about a core comprising cardboard rings, flanges or a metal clamping ring. For polishing disks, layers of textiles are cut to size, placed one above the other and rotated by an angle of 30.degree., and sewn and held together by cardboard flanges affixed thereon. The textile used for this purpose is in general, but for polishing in particular, a cotton textile. Except in the earlier polishing procedures, a textile having more rigid fibers, for example sisal, can also be used. Specific polishing rings or disks, can also be fabricated from a mixture of cotton and sisal textile. The polishing rings and disks, can be impregnated with a resin serving as a bonding means to increase the strength of the tool.
It has been necessary for many years to bias textiles comprising cotton or other nonmixed or mixed fiber materials before cutting them to size and processing them into folded rings. Biasing aligns the warp and weft threads so that they extend obliquely to the selvedge and thus prevents fraying. For this procedure a special reversing machine is required which sews the edges of the textile together thus forming a tube. Subsequently the textile tube is helically cut open into webs (biased) and rolled up to form bales. The threads form an angle of 45.degree. at the periphery of the folded rings. The problem of fraying of the folded rings is intended to be counteracted by means of the biasing (cf. Journal L'Usine Nouvell, March 1961, "Techniques modernes de Bufflage et de Pollisage").
By folding pleats into the textile strips, the polishing ring is automatically ventilated during rotation and receives the requisite pliability to envelope or wrap the part to be polished and forms honeycombs at the periphery which hold the polishing paste. Polishing pastes due to their grinding and lubricating capability are always required when polishing surfaces.
Conventional polishing tools, however, have economic as well as technical disadvantages. These are in particular the following:
impeded procurement of goods on the world markets due to bureaucratic regulation of import quotas by the European Union with respect to cotton textiles, PA1 strong fluctuations of the quotations on the stock market of world market prices of the raw material cotton, PA1 lacking production capacities in Europe due to high wages, PA1 difficult manufacture of mixed textiles due to the yarn production process, PA1 technical necessity of biasing as an additional work step which cannot be automated which results in disturbing side effects of hard and broad bias seams which impair the production process as well as the quality of the surface treatment, PA1 considerable textile waste, PA1 non-uniform wear of the grinding rings and disks due to fraying of the textile, PA1 frequent tool change due to limited service life of the grinding rings and disks. PA1 high waste component which cannot be utilized due to the bonding means, PA1 low fleece density due to the limited penetration capability of the bonding means (filter effect), PA1 insufficient mechanical strength and lower service life, PA1 limited possibilities of application because of non-uniform distribution of the bonding means and consequent erratic results, PA1 insufficient heat stability leading to undesirable smearing effect, PA1 restricted production capability of fiber mixtures due to differing adhesion and bonding capability of the bonding means on the different types of fiber materials, and PA1 undesirable stiffening of the fibers through the bonding means. PA1 independence from unstable raw material prices since the fleece according to the invention can also be produced by using artificial or synthetic fibers, PA1 reusable waste since neither a textile structure nor bonding means are present, PA1 expanded options for fiber mixing since yarn production is omitted, PA1 omission of the working step of biasing, PA1 better processibility and application capability due to the omission of bias seams, PA1 production processes which are simple to automate, PA1 no fraying and thus uniform radial wear, PA1 consequently greater service and thus tool change times, PA1 increased quiet running due to better true running, PA1 readily removable abraded particles and thereby greater cleanliness and reduced danger of smoldering fire at the work place, and PA1 due to the flexibility of the bonding means-free and therefore not rigid random fiber fleece, good immersion behavior for uneven objects which upon immersion are enveloped by the fleece. The flexibility is preferably such that an immersion depth of up to at least 50 mm can be achieved.
Polishing tools composed of fleece are rarely used. FR 1 426 721 describes in this regard, for example, a polishing or grinding material comprised of fleece which comprises permanently undulated synthetic filaments. In the process, an adhesive substance with or without grinding particles is applied onto the filaments held in tension. When the tension is relaxed the fibers become interlaced and are subsequently thermofixed. The fleece obtained in this way is cut into an annular polishing tool and processed. FR 2 310 838 also discloses polishing rings which comprise several layers of fleece. The nonsystematically arranged fibers of this fleece are connected at their points of intersection by means of a resin.
In spite of some improvements to textile rings and disks, such fleece polishing rings and disks nevertheless still have the following disadvantages:
EP-A-0 178 577 discloses a felt body, in particular a felt ring, provided with grinding or polishing paste for polishing and grinding work. In addition, the body comprises at least 35% wool or similar hair elements to facilitate the integration of the grinding and polishing grains into the felt. Also grinding and polishing grains of a grain size less than 1000 .mu.m are enclosed in hollow spaces of the random-fiber felt. The felt body is treated with a stiffening means with the fraction of stiffening additives to the felt body being at least 40%. As stiffening additives, water-soluble thermoplastic additives with a dry content of 20 to 50% polyvinyl acetate dispersions are used. The resulting stiffness of the felt body makes it unsuitable for many applications.